Manufacture of seamless tubes.



atented Dec. 29, 1914.

S um W A r. .0 .R

L nmumc'ru LmA'l-lou inn) 0 mm A FIELI.

To all-whom itmdyconcem: H

Be "it k ll-W1} that, I, Lisommb- Diet 1 s residing at Erie, ingthe county-ofErie arid- Statef of United States, have -.invented' or discovered- Pennsylw ania', Citizen of. the

, .eeitai new,- and useful Improvements': 1n i .tM'aIiufaoture I of "Seamless Tubes, "of "whieh 11 provementswthe fol-lowing is a specifiea SeamIeSe t ihes from hollow billets and hie .eet the. application of. [reducing i ment oj metal te pi'eveiitany detrimental 1 gripping-i Qf the mandrel bythe billet, the di splaoementfl due to the applied pressure willjbe almost holly substantially. parallel to the-axis -of; the {billet and. ,there will .be

relatively" little resistance, to thislongitudi :nal flow bf the metal.

ltisrwelll own to blackemiths t e ham-j "flier en, that lif a flow of metal in .a parti ciilar di 'eetion is desired, I the area. 9f eon-.

' taet of one ;.of the I reducing; 'surfa e'es' (as the I- 1lle 'r),, with the metal, I must be less in lIt {will b readiljfiu idei stood that if the v "Wall of metal tube is reduced by haihii er-v ing or pressing it, iiponan interior; round bar of ma idrel, siieh mandi'el itself; ,tends to act soniewliatlike a fullertoeizpand the ir nin pl tes o y n ib ll ol e *fl i st entirely;-at 'right angles t'q the' rollti be transversely if the external pressure sheets between pair of the 'flowof the.- metal is I axes; PI-f in the icase" ofa'tube upon. a mand'relgfiiistead of airel atively flat external reg ldlicing face; a.'fullei"'hav1ng-- an' e'dge eon-J.

eav'e' efoSsWise-of the {tube and ham-0W the (lifection lengthwiseof tlie mandirelf-be app-lied tot reduce the tube, the l metal 'displaic edjby 2 wise of, he ma d r'el with-"comparative free-k.

' 'doi i ,'-whe,rea e the relatively great extent of time? e dgeflof the fullerf erossyvise of; and the' consequent confinitei tieh it deseiibed herein relates j to Very similarly, in

if; thlatedge and therefore lengthv ,.'spaced around and equally spac'ed along'the eliiieoflongitudinal movement of the billet. .s0.-that ,eaohrrin'g will not-only serve as a rememe? iamese-me, s I V a ,l i p fl i e e r we Patehteem. 1295-1914 [A11 piifeeti nhliiiLOiitnbiar ezjieiagserg i 11 .721,2e8. 4 Renewed eat r 8,- 191 serial mm.

' ing of the metal thereby against the mapdrel ten d te' Prevent any 'subst'antialgflow oi-metal 'ciitcumferentially.j These emsid' ei-atioiis will' aid in linderstandingthe .pres

ent' invention. 1 v i l lgereto'fore in reducing billets by ne holl ng in the "Mannesmaiih.method, the ag tent ofcontact of the'metallontlie rolls aiid r aiidrel has been such thatgreater lon gitudinalthan circumferential resistance is pofi'ered to the flow" of metal. "Under'such' I conditions the greater flowxishii'cumferem.

tlal and to produce material elongation the m tal ml st crowd itsywayforwai'daiid spia ly' arol ndthe-imindrel and ,is'thereby subected to'gr'eat and injurious stress. v In "theacc'ompanying drawings forming a -part ofthis specification, Figure l is 2 s de 'elepation of the parts" orf-e'leinent's" (if .:L nachinej-i'mmediately operative 0n the metal .-in the practice [of my improved met-hod, andEigJ -Z is aJseetionalj plan View .of another xforni gofappar atus, adapted be carry/ out said' method. v I In the practice oimy in vention reduction {w of the billet isefikactedbj the conjoint aetlonflof conyex'ihterior and concave exterior surfaces, the'l'atter operating obliquely. on 'the-l'jillet'and 'movin" -ini-plzuies 'at an angle, to the axis 'offtheiillet" I i .35 vMy improved method be carried out by several" ,fqrn e 01". constructions of appal zitliS. as. forexample' byJ-the'Lfm'm' 'shown and described herein; 01i,..-by';-the"fotni of ap-/ p'aratus forming the-'siibjeet ihatter 0f, :aIi 9g "July 12,- 1 912'; wherein-apparatus is claimed.

I i thejcons'truction shown in Fig, 1, the exter'io'rly acting jieducin'g membersconsist "of'a pliu ality of' 'ings or annular members 1 5 'suitab'ly supported as for example in cii-cu-l lar housin'gs as shownin the application Te ferred to. The housings are so eon strueted and arranged that theplane ofjrotation nf the reducing rings. will be-so inelined to the axis'of the billet as to impart to the lattea I longitudinal movement. The rings' -areso I mounted e'ccenti'ically' as regards the axis of the billet that the pointe' ofleast eccentricity- ,"or the' points at which the'inner slurfhces of we the rings Contact with the billet are equally tinting element, but'will also operate 3081111 f by the cross-sectlon;

' port the billet while being .acted on by the other rings. Additional supports for the billet while being reduced are provided b any suitable means, such as a plurality of rings 2, so mounted as to be capable of rota-- tion,.preferably by frictional contact with w the billet. These supporting rings are so ar-' ranged that their oblique rolling actions and planes of rotation will have substantially "the same inclination to the axis of the billet as the reducing rings in order that the longitudinal movement of the billet may not be retarded. The rings 1 have external gear teeth, as shown, fordriving them, and have narrow and rounded rolling faces, as shown In reduclfnr metal tubes by cross rolls which are I nvex' transversely of the billet,

the pressure is applied at an acute angle, in-

stead of perpendicularly, to the surface of gthe inetal at the point where the roll impinges on the metal, thus driving the metal alongtbefore the roll in a transverse'direc tio'n'.''= The greater the convexity of the roll, 7

'- pressure where the roll first implnges on the metal; and, in any case, where the extent of contact is smaller at right angles to the axis the" more acute will be this angle of applied of the billet than longitudinally thereof, displacement will be inthe rolling direction transversely of the billet; For reasons hereinbefore stated displacement of metal in'the Mannesman'n'method is spirally around the billet. I

, In my "impi ved method employing an terior convex and an exterior concave sur cave surfacebe as nearly as practicable the face, if. the radius of curvature of the consame as the .radius of the outer surface of the billet,'- the area ofcontact between the concave surfaceand the billet is very large circumferentiallyf and the angle between the approaching reducing surface and billet surface as th 'yl ome into-contact isso small 3 that the impingement is very easy and.gradual', and the action of the reducingsurface l on the metal closely resembles the application of pressure radiallyina continuous progression around the billet. -.When reducing hollow billets by convex cross rolls as in the 'Mannesmann method,

the extent of contact of the rolls on the metal is much greater lengthwise-'ofithe billet. than it is. transversely hence there is great resist- 55 ture of a concave surface to the external;v

diameter of the billet the transverse e t of contact of. the surface with th bill-let bemade substantiallyequal to cases greater than one fourth of the-circling .evenif the preferred relative of the contact surface b'e-varied. 1

ference'of the billet. As for example in reducmg ablllet havingan external diameter y of four inches, the concave reducing surface can be made to have a contact tran erse of i the billet equal to or greater than three inches. Then by making the reducing portion of the concave surface with a transverse width of about two inches and slightly oval or with rounded edges there' will be less resistance to longitudinal movement of the metal than to its transverse movement; In other words in the practice'ofmy improved method, reducing pressure is-so-applied to the billet that. displacement of metal will produce elongation and very little transverse displacement. VVhile it is-preferred that'the concave surface should have its ex-' tent of contact greater transversely than' longitudinally such relative proportioning of the extent of'contact is not necessary'to getting some advantage from concave rolls,

as when using a concave reducing su'rfac'efas described,-there will be less resistance-to longitudinal movement of the metal thanwith any other forms of reducing surface,

proportioning In lieu of employing a series of longitudi-I nally spaced rings as shown in Fig; 1, a con- .struction requiring the employment of a stifi' mandrel .for small thin tubes, the

method described herein can be carried out by the form of apparatus shown in Fig.2,

and forming the subject-matter of an application filed November 29, 1912, and patented July-22, 1913, No. 1,067,806, to Fr. S. Diescher. This mill consists of two substantially annular housings 4, provided witlr'bearings v )5 for the annular hubs. '6 of; the disks 7.

These disks are formed with'central o enings, the walls of which are shaped to orm annular reducing surfaces a,. Wh1 ch howevermay be formed on rings '8, secured in seats on the disks. The housings'are arranged in' such relation to eachother "that the axes of thering s are out of alinement, so that the I line of movement of the billet andmandrel through the. rings forms. an acute thatthe rings are not parallel, but slightly inclined .oppositely each other 'tran sv vers'ely'to the section plane of'the drawmg,

so that the cross rolling action will bec'orreanglewith the axes ofthe rings. The reducing surfaces" at are formed. on' such an angle with reference to the axes ofthejrings as toform a convergingmouthed pass for 1 the billet. .It will'be'observedin-the-figurespondingly oblique "on the: bil1et,-*and, as

shown in the section, the rolling faces are I i makenarro'w contact 'longitudinally'of the jass. It'will'be observedlthatthereduc ng urfaceorone rin whenvop'era'tive on: the.

substantially narrow. and convex so; :as to bille -is diamante 1y p medu *isryiiiwpf the 9 7= Th rPferiPh rie of the disks 7 are toothed. to intermesh with pinions 9 on the shafts 10, whereby the disks are rotated in their bearings.

versely, thereby expanding it away from Even when disks are used billets the lines of pressure will diverge from a line passing through the axis of the billet and the points where the surfaces of the disks are nearest the center of the billet.

It' is characteristic of my improved method involving the employment of con} the mandrel. to reduce the vex and; concave reducing surfaces that pressure 1s so applied that the line of the external pressure through any one point of contact of the concave surface will converge in the direction of through any other points of contact of that surface in the same plane transverse of the billet. Hence in my improved method the concave surface 'ivill have slight tendency to cause material ternal diameter of the billet.

I claim herein. as my invention:

1. As an improvement in the art of making seamless tubes, the method vof cross-rolling which consists in subjecting the tubular billet to oblique cross-rolling and pressure between an internal mandrel and an external cross-rolling surface which is narrow'lengthwise of the tube and is concave in the oblique cross-rolling plane, applying the external rolling pressure over a contact area which is relatively. narrow lengthwise v relatively thereby simultaneously elongating and adthe billet toward lines enlargement of the 111-.-

of the tube and relatively wide circumferentially, and thereby simultaneously elon: gating and advancing the tube.

2. As an improvement in the art of making seamless tubes, the method of crossrolling which consists in subjecting the tubular billet to oblique cross-rollingand pressure by an external cross-rolling sur-- face which is concave in the plane of its'obhque cross-rolling motion,- applying the ressure over a contact area which is relatively narrow lengthwise of the tube-and wide circumterentially, I

vancing the tube.

, As an improvement in the art of mak- .ing seamless tubes, 'the method of crossrolling which consists in subjecting I the tubular billet t'o.cross-r olling and pressure between an internal mandrel and an external cross-rolling surface which is convex and narrow lengthwise'of the mandrel and concave in the plane of its cross-rolling motion, and therebysimultaneously decreasing the Wall thickness and elongating the tube.

4. As an improvementin the art of mak'-' ing seamless tubes, the method of crossroll-ing which consists in subjecting {the tubular billet to oblique cross-rolling and pressure between an internal mandrel and an external concave which is concave in lique cross-rolling motion "and restricting the external pressure to a contact area on,

the tubular billet which is relatively narrow lengthwise of the mandrel and extensive circumferentially ofthemandrel.

In testimony whereof, I have hereunto set and cross-rolling surface the plane of the o 

